Physical mechanism of Chelyabinsk superbolide explosion

2015

Abstract. Impacts of falling evaporating bodies (FEBs) with stars and planets at velocities V 10 − 20 km/s will be accompanied, due to aerodynamic effects such as crushing and transversal expansion of the crushed mass, by the FEB's "explosion" and the generation of a strong "blast" wave, resulting in FEB-generated explosive/flare phenomena. Multiwavelength monitoring of nearby young stars (and exoplanets) with dense protoplanetary disks rich in FEB's is hence of interest for identifying such FEB-related mechanisms possibly underlying their variability.

Section: Explosions Of Febs In Stellar and Planetary Atmospheresmentioning

confidence: 99%

“…This approach was further developed in connection with the 100th anniversary of the Tunguska phenomenon. The complete analytic theory of bolide explosions was presented and used to explain the February 15, 2013 Chelyabinsk event (Grigorian et al 2013 and references therein).…”

Section: Introductionmentioning

confidence: 99%

Young Stars and Planets Near the Sun: Explosive Phenomena from Falling Evaporating Bodies

2015

“…The physics of a similar explosive event in the Earth's atmosphere, known as the 1908 Tunguska phenomenon, has analytically been developed during several last decades (Grigorian 1979;Ibadov et al 2008Ibadov et al , 2010Grigorian et al 2009Grigorian et al , 2013.…”

Section: Impulse Aerodynamic Deceleration Of Crushed Comet Nuclei In mentioning

confidence: 99%

Stellar ejecta from falling comet-like bodies: young stars

2013

High-resolution spectral observations of young stars with dense protoplanetary discs like Beta Pictoris led to the discovery of variable emission lines of metal atoms, Na, Fe etc., that indicate the presence of fluxes of comet-like evaporating bodies falling onto the stars, FEBs. Assuming the presence of stellar atmospheres similar to the solar one, we show that passages of the FEBs through the stellar chromosphere and photosphere with velocities around 600 km/s will be accompanied by aerodynamic crushing of the nuclei, transverse expansion of the crushed matter, “explosion” of the flattened nuclei in a relatively very thin sub-photosphere layer due to sharp deceleration, and impulse production of a hot plasma. The impulsive rise of the layer's temperature and density lead to the generation of a strong “blast” shock wave and shock wave-induced ejection/eruption of hot plasma into space above the chromosphere. Observations of such impact-induced high-temperature phenomena are of interest for the physics/prognosis of stellar/solar flares as well as physics of comets.

“…Ibadov et al 2009;Ibadov 2012;Ibodov & Ibadov 2011;Grigoryan et al 2013). Using (2.1) with ρ n = 0.5 g/cm 3 , R n = 10 5 cm, V * = V 0 , A = 20, z = 5, x 1 = 3 we have Δh e = 140 km, E e = 7 · 10 29 erg, T 0 = 7 · 10 6 K. Hence, "superflares" may be due to impacts with comets like comet Hale-Bopp 1995 OI (cf.…”

Section: Massive Stars Comet-induced Flaresmentioning

confidence: 99%

Massive stars: flare activity due to infalls of comet-like bodies

2014

Abstract. Passages of comet-like bodies through the atmosphere/chromosphere of massive stars at velocities more than 600 km/s will be accompanied, due to aerodynamic effects as crushing and flattening, by impulse generation of hot plasma within a relatively very thin layer near the stellar surface/photosphere as well as "blast" shock wave, i.e., impact-generated photospheric stellar/solar flares. Observational manifestations of such high-temperature phenomena will be eruption of the explosive layer's hot plasma, on materials of the star and "exploding" comet nuclei, into the circumstellar environment and variable anomalies in chemical abundances of metal atoms/ions like Fe, Si etc. Interferometric and spectroscopic observations/monitoring of young massive stars with dense protoplanetary discs are of interest for massive stars physics/evolution, including identification of mechanisms for massive stars variability.